We’re all born with a ‘chuckle muscle’ and if you laugh and exercise it everyday it will keep you young and frisky all of your life, but if you don’t it will dry up and drop off. Who says so?

The undisputed ‘King of Comedy’ Ken Dodd, the last of the old-time comedians celebrates his 80th birthday today, as well as over 55 years in show business. This comic icon’s career started with the advent of television and his role as the buck-toothed, frizzy-haired laughter machine with his legendary coloured ‘tickling stick’ still tours the country on a gruelling 200 shows a year schedule, selling out at every venue with marathon shows that are as long as he wishes to make them.

My wife and I have now seen him six times and you just cannot fail to be impressed by the craftsmanship that only half a century on stage can bring. So what makes this buck-toothed clown so special? Once he starts he is unstoppable with a fast and furious delivery of one-liner jokes, estimated at six jokes a minute starting with the customary “How tickled I am! Have you ever been tickled missus?” as he waves his iconic coloured feather duster ‘tickling stick’ in a never ending delivery of gags in a show that will last well over five hours! His wordplay is inspired with “I’m feeling tattyfilarious, full of plumpiousness and utterly discumknockerated”

He taunts his audience with “the great thing about my shows is that everyone goes home in daylight” working on his victims like the master interrogator. On the three hour mark he tells them “well that’s the warm up over, lets start the show” and your off exercising that chuckle muscle once again.

As he starts banging on his huge bass drum singing ‘Silent Night’ he has you in his clutches telling tales about Professor Yaffle Chuckabutty Operatic Tenor and Sausage Knotter. He loves to mock the ‘mother-in-laws’ with “I haven’t spoken to my mother-in-law for 18 months, I don’t like to interrupt” and “ I love Honolulu it has everything, sand for the kids, sun for the mums and sharks for the mother-in-law”.

You soon realise that it’s not the corny jokes causing the laughter that is now hurting your sides but the man himself. Tales of adventure of his dwarf friends ‘The Diddymen’ from Knotty Ash including Dicky Mint, Mick the Marmalizer, Hamish McDiddy and Nigel Ponsonby-Smallpiece who all work in the ‘Jam Butty Mines’, at the ‘Moggy Ranch’ and down at the ‘Treacle Wells’ have his admirers rocking in the aisles.

Midnight arrives and finally exhaustion sets in, yours that is not Doddy's as he yells, “You think you can get away, you can’t, I’ll just follow you home and shout jokes through the letterbox”. He never once loses his audience from either fatigue or a misfired joke adapting his gags to which part of the country he is performing by means of his ‘Giggle Map’ of Great Britain.

And that's Dodd's strength. You're always with him, and eventually he will break down your resistance. It's the sort of stagecraft every comic should study. I've lost count of the number of comics I've seen go along the front row asking punters what they do for a living, but seeing Doddy do it with such lightning and genuine wit, without ever being cruel, as that would never be his style is astoundingly impressive.

Not only is Doddy Britain’s most successful, enduring and most loved stage comedian but his achievements include nineteen top twenty hits to his name including the weepy ‘Tears’ which topped the British charts in 1965 and was the biggest selling single that year at a time when The Beatles were dominant. He holds the record for the most Royal Command Performances as well as umpteen prestigious comedy awards, an O.B.E. and the world record for the longest non-stop joke telling performance of over 1500 gags.

Clearly nobody has as long a career as Doddy simply by relying on a few naff catchphrases. Where most entertainers his age might be happy slinking off into semi-retirement, Doddy is still relentlessly touring demonstrating night after night that he is the undisputed king of stand-up comedy.

As he takes his final curtain call in the early hours the audience is standing and cheering for more and as he retreats behind the falling curtain ‘tickling stick’ in hand waving and shouting “Tatty bye everybody, tatty bye, tatty bye”.